//
// Copyright (c) Microsoft Corporation.  All rights reserved.
//
//
// Use of this source code is subject to the terms of the Microsoft end-user
// license agreement (EULA) under which you licensed this SOFTWARE PRODUCT.
// If you did not accept the terms of the EULA, you are not authorized to use
// this source code. For a copy of the EULA, please see the LICENSE.RTF on your
// install media.
//
//==========================================================================;
//
//  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
//  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
//  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
//  PURPOSE.
//
//
//--------------------------------------------------------------------------;

// Base classes implementing IDispatch parsing for the basic control dual
// interfaces. Derive from these and implement just the custom method and
// property methods. We also implement CPosPassThru that can be used by
// renderers and transforms to pass by IMediaPosition and IMediaSeeking


#include <streams.h>
#include <limits.h>
#include "seekpt.h"

// 'bool' non standard reserved word
#pragma warning(disable:4237)


// --- CBaseDispatch implementation ----------
CBaseDispatch::~CBaseDispatch()
{
    if (m_pti) {
        m_pti->Release();
    }
}


// return 1 if we support GetTypeInfo

STDMETHODIMP
CBaseDispatch::GetTypeInfoCount(UINT * pctinfo)
{
    CheckPointer(pctinfo,E_POINTER);
    ValidateReadWritePtr(pctinfo,sizeof(UINT *));
    *pctinfo = 1;
    return S_OK;
}


typedef HRESULT (STDAPICALLTYPE *LPLOADTYPELIB)(
                                                const OLECHAR FAR *szFile,
                                                ITypeLib FAR* FAR* pptlib);

typedef HRESULT (STDAPICALLTYPE *LPLOADREGTYPELIB)(REFGUID rguid,
                                                   WORD wVerMajor,
                                                   WORD wVerMinor,
                                                   LCID lcid,
                                                   ITypeLib FAR* FAR* pptlib);

// attempt to find our type library

STDMETHODIMP
CBaseDispatch::GetTypeInfo(
                           REFIID riid,
                           UINT itinfo,
                           LCID lcid,
                           ITypeInfo ** pptinfo)
{
    CheckPointer(pptinfo,E_POINTER);
    ValidateReadWritePtr(pptinfo,sizeof(ITypeInfo *));
    HRESULT hr;
    
    *pptinfo = NULL;
    
    // we only support one type element
    if (0 != itinfo) {
        return TYPE_E_ELEMENTNOTFOUND;
    }
    
    if (NULL == pptinfo) {
        return E_POINTER;
    }
    
    // always look for neutral
    if (NULL == m_pti) {
        
        LPLOADTYPELIB       lpfnLoadTypeLib;
        LPLOADREGTYPELIB    lpfnLoadRegTypeLib;
        ITypeLib        *ptlib;
        HINSTANCE       hInst;
        
        static const TCHAR szTypeLib[]    = TEXT("LoadTypeLib");
        static const TCHAR szRegTypeLib[] = TEXT("LoadRegTypeLib");
        static const TCHAR szControl[]    = TEXT("control.tlb");
        
        //
        // Try to get the Ole32Aut.dll module handle.
        //
        
        hInst = LoadOLEAut32();
        if (hInst == NULL) {
            DWORD dwError = GetLastError();
            return HRESULT_FROM_WIN32(dwError);
        }
        lpfnLoadRegTypeLib = (LPLOADREGTYPELIB)GetProcAddress(hInst,
            szRegTypeLib);
        if (lpfnLoadRegTypeLib == NULL) {
            DWORD dwError = GetLastError();
            return HRESULT_FROM_WIN32(dwError);
        }
        
        hr = (*lpfnLoadRegTypeLib)(LIBID_QuartzTypeLib, 1, 0, // version 1.0
            lcid, &ptlib);
        
        if (FAILED(hr)) {
            
            // attempt to load directly - this will fill the
            // registry in if it finds it
            
            lpfnLoadTypeLib = (LPLOADTYPELIB)GetProcAddress(hInst, szTypeLib);
            if (lpfnLoadTypeLib == NULL) {
                DWORD dwError = GetLastError();
                return HRESULT_FROM_WIN32(dwError);
            }
            
            hr = (*lpfnLoadTypeLib)(szControl, &ptlib);
            if (FAILED(hr)) {
                return hr;
            }
        }
        
        hr = ptlib->GetTypeInfoOfGuid(
            riid,
            &m_pti);
        
        ptlib->Release();
        
        if (FAILED(hr)) {
            return hr;
        }
    }
    
    *pptinfo = m_pti;
    m_pti->AddRef();
    return S_OK;
}


STDMETHODIMP
CBaseDispatch::GetIDsOfNames(
                             REFIID riid,
                             OLECHAR  ** rgszNames,
                             UINT cNames,
                             LCID lcid,
                             DISPID * rgdispid)
{
    // although the IDispatch riid is dead, we use this to pass from
    // the interface implementation class to us the iid we are talking about.
    
    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(riid, 0, lcid, &pti);
    
    if (SUCCEEDED(hr)) {
        hr = pti->GetIDsOfNames(rgszNames, cNames, rgdispid);
        
        pti->Release();
    }
    return hr;
}

// --- CMediaControl implementation ---------

CMediaControl::CMediaControl(const TCHAR * name,LPUNKNOWN pUnk) :
CUnknown(name, pUnk)
{
}

// expose our interfaces IMediaControl and IUnknown

STDMETHODIMP
CMediaControl::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if (riid == IID_IMediaControl) {
        return GetInterface( (IMediaControl *) this, ppv);
    } else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


// return 1 if we support GetTypeInfo

STDMETHODIMP
CMediaControl::GetTypeInfoCount(UINT * pctinfo)
{
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


// attempt to find our type library

STDMETHODIMP
CMediaControl::GetTypeInfo(
                           UINT itinfo,
                           LCID lcid,
                           ITypeInfo ** pptinfo)
{
    return m_basedisp.GetTypeInfo(
        IID_IMediaControl,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CMediaControl::GetIDsOfNames(
                             REFIID riid,
                             OLECHAR  ** rgszNames,
                             UINT cNames,
                             LCID lcid,
                             DISPID * rgdispid)
{
    return m_basedisp.GetIDsOfNames(
        IID_IMediaControl,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CMediaControl::Invoke(
                      DISPID dispidMember,
                      REFIID riid,
                      LCID lcid,
                      WORD wFlags,
                      DISPPARAMS * pdispparams,
                      VARIANT * pvarResult,
                      EXCEPINFO * pexcepinfo,
                      UINT * puArgErr)
{
    // this parameter is a dead leftover from an earlier interface
    if (IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }
    
    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);
    
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pti->Invoke(
        (IMediaControl *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);
    
    pti->Release();
    return hr;
}

// --- CMediaEvent implementation ----------


CMediaEvent::CMediaEvent(const TCHAR * name,LPUNKNOWN pUnk) :
CUnknown(name, pUnk)
{
}


// expose our interfaces IMediaEvent and IUnknown

STDMETHODIMP
CMediaEvent::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if (riid == IID_IMediaEvent || riid == IID_IMediaEventEx) {
        return GetInterface( (IMediaEventEx *) this, ppv);
    } else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


// return 1 if we support GetTypeInfo

STDMETHODIMP
CMediaEvent::GetTypeInfoCount(UINT * pctinfo)
{
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


// attempt to find our type library

STDMETHODIMP
CMediaEvent::GetTypeInfo(
                         UINT itinfo,
                         LCID lcid,
                         ITypeInfo ** pptinfo)
{
    return m_basedisp.GetTypeInfo(
        IID_IMediaEvent,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CMediaEvent::GetIDsOfNames(
                           REFIID riid,
                           OLECHAR  ** rgszNames,
                           UINT cNames,
                           LCID lcid,
                           DISPID * rgdispid)
{
    return m_basedisp.GetIDsOfNames(
        IID_IMediaEvent,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CMediaEvent::Invoke(
                    DISPID dispidMember,
                    REFIID riid,
                    LCID lcid,
                    WORD wFlags,
                    DISPPARAMS * pdispparams,
                    VARIANT * pvarResult,
                    EXCEPINFO * pexcepinfo,
                    UINT * puArgErr)
{
    // this parameter is a dead leftover from an earlier interface
    if (IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }
    
    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);
    
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pti->Invoke(
        (IMediaEvent *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);
    
    pti->Release();
    return hr;
}

// --- CMediaPosition implementation ----------


CMediaPosition::CMediaPosition(const TCHAR * name,LPUNKNOWN pUnk) :
CUnknown(name, pUnk)
{
}

CMediaPosition::CMediaPosition(const TCHAR * name,
                               LPUNKNOWN pUnk,
                               HRESULT * phr) :
CUnknown(name, pUnk)
{
    UNREFERENCED_PARAMETER(phr);
}


// expose our interfaces IMediaPosition and IUnknown

STDMETHODIMP
CMediaPosition::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if (riid == IID_IMediaPosition) {
        return GetInterface( (IMediaPosition *) this, ppv);
    } else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}

// return 1 if we support GetTypeInfo

STDMETHODIMP
CMediaPosition::GetTypeInfoCount(UINT * pctinfo)
{
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


// attempt to find our type library

STDMETHODIMP
CMediaPosition::GetTypeInfo(
                            UINT itinfo,
                            LCID lcid,
                            ITypeInfo ** pptinfo)
{
    return m_basedisp.GetTypeInfo(
        IID_IMediaPosition,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CMediaPosition::GetIDsOfNames(
                              REFIID riid,
                              OLECHAR  ** rgszNames,
                              UINT cNames,
                              LCID lcid,
                              DISPID * rgdispid)
{
    return m_basedisp.GetIDsOfNames(
        IID_IMediaPosition,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CMediaPosition::Invoke(
                       DISPID dispidMember,
                       REFIID riid,
                       LCID lcid,
                       WORD wFlags,
                       DISPPARAMS * pdispparams,
                       VARIANT * pvarResult,
                       EXCEPINFO * pexcepinfo,
                       UINT * puArgErr)
{
    // this parameter is a dead leftover from an earlier interface
    if (IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }
    
    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);
    
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pti->Invoke(
        (IMediaPosition *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);
    
    pti->Release();
    return hr;
}

// --- IMediaPosition and IMediaSeeking pass through class ----------


CPosPassThru::CPosPassThru(const TCHAR *pName,
                           LPUNKNOWN pUnk,
                           HRESULT *phr,
                           IPin *pPin) :
CMediaPosition(pName,pUnk),
m_pPin(pPin)
{
    if (pPin == NULL) {
        *phr = E_POINTER;
        return;
    }
}


// Expose our IMediaSeeking and IMediaPosition interfaces

STDMETHODIMP
CPosPassThru::NonDelegatingQueryInterface(REFIID riid,void **ppv)
{
    CheckPointer(ppv,E_POINTER);
    *ppv = NULL;
    
    if (riid == IID_IMediaSeeking) {
        return GetInterface( static_cast<IMediaSeeking *>(this), ppv);
    }
    return CMediaPosition::NonDelegatingQueryInterface(riid,ppv);
}


// Return the IMediaPosition interface from our peer

HRESULT
CPosPassThru::GetPeer(IMediaPosition ** ppMP)
{
    *ppMP = NULL;
    
    IPin *pConnected;
    HRESULT hr = m_pPin->ConnectedTo(&pConnected);
    if (FAILED(hr)) {
        return E_NOTIMPL;
    }
    IMediaPosition * pMP;
    hr = pConnected->QueryInterface(IID_IMediaPosition, (void **) &pMP);
    pConnected->Release();
    if (FAILED(hr)) {
        return E_NOTIMPL;
    }
    
    *ppMP = pMP;
    return S_OK;
}


// Return the IMediaSeeking interface from our peer

HRESULT
CPosPassThru::GetPeerSeeking(IMediaSeeking ** ppMS)
{
    *ppMS = NULL;
    
    IPin *pConnected;
    HRESULT hr = m_pPin->ConnectedTo(&pConnected);
    if (FAILED(hr)) {
        return E_NOTIMPL;
    }
    IMediaSeeking * pMS;
    hr = pConnected->QueryInterface(IID_IMediaSeeking, (void **) &pMS);
    pConnected->Release();
    if (FAILED(hr)) {
        return E_NOTIMPL;
    }
    
    *ppMS = pMS;
    return S_OK;
}


// --- IMediaSeeking methods ----------


STDMETHODIMP
CPosPassThru::GetCapabilities(DWORD * pCaps)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->GetCapabilities(pCaps);
    pMS->Release();
    return hr;
}

STDMETHODIMP
CPosPassThru::CheckCapabilities(DWORD * pCaps)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->CheckCapabilities(pCaps);
    pMS->Release();
    return hr;
}

STDMETHODIMP
CPosPassThru::IsFormatSupported(const GUID * pFormat)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->IsFormatSupported(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::QueryPreferredFormat(GUID *pFormat)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->QueryPreferredFormat(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::SetTimeFormat(const GUID * pFormat)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->SetTimeFormat(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::GetTimeFormat(GUID *pFormat)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->GetTimeFormat(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::IsUsingTimeFormat(const GUID * pFormat)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->IsUsingTimeFormat(pFormat);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::ConvertTimeFormat(LONGLONG * pTarget, const GUID * pTargetFormat,
                                LONGLONG    Source, const GUID * pSourceFormat )
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->ConvertTimeFormat(pTarget, pTargetFormat, Source, pSourceFormat );
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::SetPositions( LONGLONG * pCurrent, DWORD CurrentFlags
                           , LONGLONG * pStop, DWORD StopFlags )
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->SetPositions(pCurrent, CurrentFlags, pStop, StopFlags );
    pMS->Release();
    return hr;
}

STDMETHODIMP
CPosPassThru::GetPositions(LONGLONG *pCurrent, LONGLONG * pStop)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->GetPositions(pCurrent,pStop);
    pMS->Release();
    return hr;
}

HRESULT
CPosPassThru::GetSeekingLongLong
( HRESULT (__stdcall IMediaSeeking::*pMethod)( LONGLONG * )
 , LONGLONG * pll
 )
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (SUCCEEDED(hr))
    {
        hr = (pMS->*pMethod)(pll);
        pMS->Release();
    }
    return hr;
}

// If we don't have a current position then ask upstream

STDMETHODIMP
CPosPassThru::GetCurrentPosition(LONGLONG *pCurrent)
{
    // Can we report the current position
    HRESULT hr = GetMediaTime(pCurrent,NULL);
    if (SUCCEEDED(hr)) hr = NOERROR;
    else hr = GetSeekingLongLong( &IMediaSeeking::GetCurrentPosition, pCurrent );
    return hr;
}


STDMETHODIMP
CPosPassThru::GetStopPosition(LONGLONG *pStop)
{
    return GetSeekingLongLong( &IMediaSeeking::GetStopPosition, pStop );;
}

STDMETHODIMP
CPosPassThru::GetDuration(LONGLONG *pDuration)
{
    return GetSeekingLongLong( &IMediaSeeking::GetDuration, pDuration );;
}


STDMETHODIMP
CPosPassThru::GetPreroll(LONGLONG *pllPreroll)
{
    return GetSeekingLongLong( &IMediaSeeking::GetPreroll, pllPreroll );;
}


STDMETHODIMP
CPosPassThru::GetAvailable( LONGLONG *pEarliest, LONGLONG *pLatest )
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMS->GetAvailable( pEarliest, pLatest );
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::GetRate(double * pdRate)
{
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMS->GetRate(pdRate);
    pMS->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::SetRate(double dRate)
{
    if (0.0 == dRate) {
        return E_INVALIDARG;
    }
    
    IMediaSeeking* pMS;
    HRESULT hr = GetPeerSeeking(&pMS);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMS->SetRate(dRate);
    pMS->Release();
    return hr;
}




// --- IMediaPosition methods ----------


STDMETHODIMP
CPosPassThru::get_Duration(REFTIME * plength)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pMP->get_Duration(plength);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::get_CurrentPosition(REFTIME * pllTime)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->get_CurrentPosition(pllTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::put_CurrentPosition(REFTIME llTime)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->put_CurrentPosition(llTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::get_StopTime(REFTIME * pllTime)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->get_StopTime(pllTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::put_StopTime(REFTIME llTime)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->put_StopTime(llTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::get_PrerollTime(REFTIME * pllTime)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->get_PrerollTime(pllTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::put_PrerollTime(REFTIME llTime)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->put_PrerollTime(llTime);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::get_Rate(double * pdRate)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->get_Rate(pdRate);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::put_Rate(double dRate)
{
    if (0.0 == dRate) {
        return E_INVALIDARG;
    }
    
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->put_Rate(dRate);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::CanSeekForward(LONG *pCanSeekForward)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->CanSeekForward(pCanSeekForward);
    pMP->Release();
    return hr;
}


STDMETHODIMP
CPosPassThru::CanSeekBackward(LONG *pCanSeekBackward)
{
    IMediaPosition* pMP;
    HRESULT hr = GetPeer(&pMP);
    if (FAILED(hr)) {
        return hr;
    }
    hr = pMP->CanSeekBackward(pCanSeekBackward);
    pMP->Release();
    return hr;
}


// --- Implements the CRendererPosPassThru class ----------


// Media times (eg current frame, field, sample etc) are passed through the
// filtergraph in media samples. When a renderer gets a sample with media
// times in it, it will call one of the RegisterMediaTime methods we expose
// (one takes an IMediaSample, the other takes the media times direct). We
// store the media times internally and return them in GetCurrentPosition.

CRendererPosPassThru::CRendererPosPassThru(const TCHAR *pName,
                                           LPUNKNOWN pUnk,
                                           HRESULT *phr,
                                           IPin *pPin) :
CPosPassThru(pName,pUnk,phr,pPin),
m_StartMedia(0),
m_EndMedia(0),
m_bReset(TRUE)
{
}


// Sets the media times the object should report

HRESULT
CRendererPosPassThru::RegisterMediaTime(IMediaSample *pMediaSample)
{
    ASSERT(pMediaSample);
    LONGLONG StartMedia;
    LONGLONG EndMedia;
    
    CAutoLock cAutoLock(&m_PositionLock);
    
    // Get the media times from the sample
    
    HRESULT hr = pMediaSample->GetTime(&StartMedia,&EndMedia);
    if (FAILED(hr))
    {
        ASSERT(hr == VFW_E_SAMPLE_TIME_NOT_SET);
        return hr;
    }
    
    m_StartMedia = StartMedia;
    m_EndMedia = EndMedia;
    m_bReset = FALSE;
    return NOERROR;
}


// Sets the media times the object should report

HRESULT
CRendererPosPassThru::RegisterMediaTime(LONGLONG StartTime,LONGLONG EndTime)
{
    CAutoLock cAutoLock(&m_PositionLock);
    m_StartMedia = StartTime;
    m_EndMedia = EndTime;
    m_bReset = FALSE;
    return NOERROR;
}


// Return the current media times registered in the object

HRESULT
CRendererPosPassThru::GetMediaTime(LONGLONG *pStartTime,LONGLONG *pEndTime)
{
    ASSERT(pStartTime);
    
    CAutoLock cAutoLock(&m_PositionLock);
    if (m_bReset == TRUE) {
        return E_FAIL;
    }
    
    // We don't have to return the end time
    
    HRESULT hr = ConvertTimeFormat( pStartTime, 0, m_StartMedia, &TIME_FORMAT_MEDIA_TIME );
    if (pEndTime && SUCCEEDED(hr)) {
        hr = ConvertTimeFormat( pEndTime, 0, m_EndMedia, &TIME_FORMAT_MEDIA_TIME );
    }
    return hr;
}


// Resets the media times we hold

HRESULT
CRendererPosPassThru::ResetMediaTime()
{
    CAutoLock cAutoLock(&m_PositionLock);
    m_StartMedia = 0;
    m_EndMedia = 0;
    m_bReset = TRUE;
    return NOERROR;
}

// Intended to be called by the owing filter during EOS processing so
// that the media times can be adjusted to the stop time.  This ensures
// that the GetCurrentPosition will actully get to the stop position.
HRESULT
CRendererPosPassThru::EOS()
{
    HRESULT hr;
    
    if ( m_bReset == TRUE ) hr = E_FAIL;
    else
    {
        LONGLONG llStop;
        if SUCCEEDED(hr=GetStopPosition(&llStop))
        {
            CAutoLock cAutoLock(&m_PositionLock);
            m_StartMedia =
                m_EndMedia   = llStop;
        }
    }
    return hr;
}

// -- CSourceSeeking implementation ------------

CSourceSeeking::CSourceSeeking(
                               const TCHAR * pName,
                               LPUNKNOWN pUnk,
                               HRESULT* phr,
                               CCritSec * pLock) :
CUnknown(pName, pUnk),
m_pLock(pLock),
m_rtStart((long)0)
{
    m_rtStop = _I64_MAX / 2;
    m_rtDuration = m_rtStop;
    m_dRateSeeking = 1.0;
    
    m_dwSeekingCaps = AM_SEEKING_CanSeekForwards
        | AM_SEEKING_CanSeekBackwards
        | AM_SEEKING_CanSeekAbsolute
        | AM_SEEKING_CanGetStopPos
        | AM_SEEKING_CanGetDuration
        | AM_SEEKING_CanGetCurrentPos;
}

HRESULT CSourceSeeking::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
    if(riid == IID_IMediaSeeking) {
        CheckPointer(ppv, E_POINTER);
        return GetInterface(static_cast<IMediaSeeking *>(this), ppv);
    }
    else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


HRESULT CSourceSeeking::IsFormatSupported(const GUID * pFormat)
{
    CheckPointer(pFormat, E_POINTER);
    // only seeking in time (REFERENCE_TIME units) is supported
    return *pFormat == TIME_FORMAT_MEDIA_TIME ? S_OK : S_FALSE;
}

HRESULT CSourceSeeking::QueryPreferredFormat(GUID *pFormat)
{
    CheckPointer(pFormat, E_POINTER);
    *pFormat = TIME_FORMAT_MEDIA_TIME;
    return S_OK;
}

HRESULT CSourceSeeking::SetTimeFormat(const GUID * pFormat)
{
    CheckPointer(pFormat, E_POINTER);
    
    // nothing to set; just check that it's TIME_FORMAT_TIME
    return *pFormat == TIME_FORMAT_MEDIA_TIME ? S_OK : E_INVALIDARG;
}

HRESULT CSourceSeeking::IsUsingTimeFormat(const GUID * pFormat)
{
    CheckPointer(pFormat, E_POINTER);
    return *pFormat == TIME_FORMAT_MEDIA_TIME ? S_OK : S_FALSE;
}

HRESULT CSourceSeeking::GetTimeFormat(GUID *pFormat)
{
    CheckPointer(pFormat, E_POINTER);
    *pFormat = TIME_FORMAT_MEDIA_TIME;
    return S_OK;
}

HRESULT CSourceSeeking::GetDuration(LONGLONG *pDuration)
{
    CheckPointer(pDuration, E_POINTER);
    CAutoLock lock(m_pLock);
    *pDuration = m_rtDuration;
    return S_OK;
}

HRESULT CSourceSeeking::GetStopPosition(LONGLONG *pStop)
{
    CheckPointer(pStop, E_POINTER);
    CAutoLock lock(m_pLock);
    *pStop = m_rtStop;
    return S_OK;
}

HRESULT CSourceSeeking::GetCurrentPosition(LONGLONG *pCurrent)
{
    // GetCurrentPosition is typically supported only in renderers and
    // not in source filters.
    return E_NOTIMPL;
}

HRESULT CSourceSeeking::GetCapabilities( DWORD * pCapabilities )
{
    CheckPointer(pCapabilities, E_POINTER);
    *pCapabilities = m_dwSeekingCaps;
    return S_OK;
}

HRESULT CSourceSeeking::CheckCapabilities( DWORD * pCapabilities )
{
    CheckPointer(pCapabilities, E_POINTER);
    
    //
    // returns S_OK if all caps are present;
    //         S_FALSE if some are present;
    //         E_FAIL if none is present;
    // *pCapabilities will reflect the caps supported
    // 
    return (~m_dwSeekingCaps & *pCapabilities) ? 
        ((*pCapabilities &= m_dwSeekingCaps) ? S_FALSE : E_FAIL) : 
    S_OK;
}

HRESULT CSourceSeeking::ConvertTimeFormat( LONGLONG * pTarget, const GUID * pTargetFormat,
                                          LONGLONG    Source, const GUID * pSourceFormat )
{
    CheckPointer(pTarget, E_POINTER);
    // format guids can be null to indicate current format
    
    // since we only support TIME_FORMAT_MEDIA_TIME, we don't really
    // offer any conversions.
    if(pTargetFormat == 0 || *pTargetFormat == TIME_FORMAT_MEDIA_TIME)
    {
        if(pSourceFormat == 0 || *pSourceFormat == TIME_FORMAT_MEDIA_TIME)
        {
            *pTarget = Source;
            return S_OK;
        }
    }
    
    return E_INVALIDARG;
}


HRESULT CSourceSeeking::SetPositions( LONGLONG * pCurrent,  DWORD CurrentFlags
                                     , LONGLONG * pStop,  DWORD StopFlags )
{
    DWORD StopPosBits = StopFlags & AM_SEEKING_PositioningBitsMask;
    DWORD StartPosBits = CurrentFlags & AM_SEEKING_PositioningBitsMask;
    
    if(StopFlags) {
        CheckPointer(pStop, E_POINTER);
        
        // accept only relative, incremental, or absolute positioning
        if(StopPosBits != StopFlags) {
            return E_INVALIDARG;
        }
    }
    
    if(CurrentFlags) {
        CheckPointer(pCurrent, E_POINTER);
        if(StartPosBits != AM_SEEKING_AbsolutePositioning &&
            StartPosBits != AM_SEEKING_RelativePositioning) {
            return E_INVALIDARG;
        }
    }
    
    
    // scope for autolock
    {
        CAutoLock lock(m_pLock);
        
        // set start position
        if(StartPosBits == AM_SEEKING_AbsolutePositioning)
        {
            m_rtStart = *pCurrent;
        }
        else if(StartPosBits == AM_SEEKING_RelativePositioning)
        {
            m_rtStart += *pCurrent;
        }
        
        // set stop position
        if(StopPosBits == AM_SEEKING_AbsolutePositioning)
        {
            m_rtStop = *pStop;
        }
        else if(StopPosBits == AM_SEEKING_IncrementalPositioning)
        {
            m_rtStop = m_rtStart + *pStop;
        }
        else if(StopPosBits == AM_SEEKING_RelativePositioning)
        {
            m_rtStop = m_rtStop + *pStop;
        }
    }
    
    
    HRESULT hr = S_OK;
    if(SUCCEEDED(hr) && StopPosBits) {
        hr = ChangeStop();
    }
    if(StartPosBits) {
        hr = ChangeStart();
    }
    
    return hr;
}


HRESULT CSourceSeeking::GetPositions( LONGLONG * pCurrent, LONGLONG * pStop )
{
    if(pCurrent) {
        *pCurrent = m_rtStart;
    }
    if(pStop) {
        *pStop = m_rtStop;
    }
    
    return S_OK;;
}


HRESULT CSourceSeeking::GetAvailable( LONGLONG * pEarliest, LONGLONG * pLatest )
{
    if(pEarliest) {
        *pEarliest = 0;
    }
    if(pLatest) {
        CAutoLock lock(m_pLock);
        *pLatest = m_rtDuration;
    }
    return S_OK;
}

HRESULT CSourceSeeking::SetRate( double dRate)
{
    {
        CAutoLock lock(m_pLock);
        m_dRateSeeking = dRate;
    }
    return ChangeRate();
}

HRESULT CSourceSeeking::GetRate( double * pdRate)
{
    CheckPointer(pdRate, E_POINTER);
    CAutoLock lock(m_pLock);
    *pdRate = m_dRateSeeking;
    return S_OK;
}

HRESULT CSourceSeeking::GetPreroll(LONGLONG *pPreroll) 
{
    CheckPointer(pPreroll, E_POINTER);
    *pPreroll = 0;
    return S_OK;
}





// --- CSourcePosition implementation ----------


CSourcePosition::CSourcePosition(const TCHAR * pName,
                                 LPUNKNOWN pUnk,
                                 HRESULT* phr,
                                 CCritSec * pLock) :
CMediaPosition(pName, pUnk),
m_pLock(pLock),
m_Start(CRefTime((LONGLONG)0))
{
    m_Stop = _I64_MAX;
    m_Rate = 1.0;
}


STDMETHODIMP
CSourcePosition::get_Duration(REFTIME * plength)
{
    CheckPointer(plength,E_POINTER);
    ValidateReadWritePtr(plength,sizeof(REFTIME));
    CAutoLock lock(m_pLock);
    
    *plength = m_Duration;
    return S_OK;
}


STDMETHODIMP
CSourcePosition::put_CurrentPosition(REFTIME llTime)
{
    m_pLock->Lock();
    m_Start = llTime;
    m_pLock->Unlock();
    
    return ChangeStart();
}


STDMETHODIMP
CSourcePosition::get_StopTime(REFTIME * pllTime)
{
    CheckPointer(pllTime,E_POINTER);
    ValidateReadWritePtr(pllTime,sizeof(REFTIME));
    CAutoLock lock(m_pLock);
    
    *pllTime = m_Stop;
    return S_OK;
}


STDMETHODIMP
CSourcePosition::put_StopTime(REFTIME llTime)
{
    m_pLock->Lock();
    m_Stop = llTime;
    m_pLock->Unlock();
    
    return ChangeStop();
}


STDMETHODIMP
CSourcePosition::get_PrerollTime(REFTIME * pllTime)
{
    CheckPointer(pllTime,E_POINTER);
    ValidateReadWritePtr(pllTime,sizeof(REFTIME));
    return E_NOTIMPL;
}


STDMETHODIMP
CSourcePosition::put_PrerollTime(REFTIME llTime)
{
    return E_NOTIMPL;
}


STDMETHODIMP
CSourcePosition::get_Rate(double * pdRate)
{
    CheckPointer(pdRate,E_POINTER);
    ValidateReadWritePtr(pdRate,sizeof(double));
    CAutoLock lock(m_pLock);
    
    *pdRate = m_Rate;
    return S_OK;
}


STDMETHODIMP
CSourcePosition::put_Rate(double dRate)
{
    m_pLock->Lock();
    m_Rate = dRate;
    m_pLock->Unlock();
    
    return ChangeRate();
}


// By default we can seek forwards

STDMETHODIMP
CSourcePosition::CanSeekForward(LONG *pCanSeekForward)
{
    CheckPointer(pCanSeekForward,E_POINTER);
    *pCanSeekForward = OATRUE;
    return S_OK;
}


// By default we can seek backwards

STDMETHODIMP
CSourcePosition::CanSeekBackward(LONG *pCanSeekBackward)
{
    CheckPointer(pCanSeekBackward,E_POINTER);
    *pCanSeekBackward = OATRUE;
    return S_OK;
}


// --- Implementation of CBasicAudio class ----------


CBasicAudio::CBasicAudio(const TCHAR * pName,LPUNKNOWN punk) :
CUnknown(pName, punk)
{
}

// overriden to publicise our interfaces

STDMETHODIMP
CBasicAudio::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if (riid == IID_IBasicAudio) {
        return GetInterface( (IBasicAudio *) this, ppv);
    } else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}

STDMETHODIMP
CBasicAudio::GetTypeInfoCount(UINT * pctinfo)
{
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


STDMETHODIMP
CBasicAudio::GetTypeInfo(
                         UINT itinfo,
                         LCID lcid,
                         ITypeInfo ** pptinfo)
{
    return m_basedisp.GetTypeInfo(
        IID_IBasicAudio,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CBasicAudio::GetIDsOfNames(
                           REFIID riid,
                           OLECHAR  ** rgszNames,
                           UINT cNames,
                           LCID lcid,
                           DISPID * rgdispid)
{
    return m_basedisp.GetIDsOfNames(
        IID_IBasicAudio,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CBasicAudio::Invoke(
                    DISPID dispidMember,
                    REFIID riid,
                    LCID lcid,
                    WORD wFlags,
                    DISPPARAMS * pdispparams,
                    VARIANT * pvarResult,
                    EXCEPINFO * pexcepinfo,
                    UINT * puArgErr)
{
    // this parameter is a dead leftover from an earlier interface
    if (IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }
    
    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);
    
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pti->Invoke(
        (IBasicAudio *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);
    
    pti->Release();
    return hr;
}


// --- IVideoWindow implementation ----------

CBaseVideoWindow::CBaseVideoWindow(const TCHAR * pName,LPUNKNOWN punk) :
CUnknown(pName, punk)
{
}


// overriden to publicise our interfaces

STDMETHODIMP
CBaseVideoWindow::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if (riid == IID_IVideoWindow) {
        return GetInterface( (IVideoWindow *) this, ppv);
    } else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


STDMETHODIMP
CBaseVideoWindow::GetTypeInfoCount(UINT * pctinfo)
{
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


STDMETHODIMP
CBaseVideoWindow::GetTypeInfo(
                              UINT itinfo,
                              LCID lcid,
                              ITypeInfo ** pptinfo)
{
    return m_basedisp.GetTypeInfo(
        IID_IVideoWindow,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CBaseVideoWindow::GetIDsOfNames(
                                REFIID riid,
                                OLECHAR  ** rgszNames,
                                UINT cNames,
                                LCID lcid,
                                DISPID * rgdispid)
{
    return m_basedisp.GetIDsOfNames(
        IID_IVideoWindow,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CBaseVideoWindow::Invoke(
                         DISPID dispidMember,
                         REFIID riid,
                         LCID lcid,
                         WORD wFlags,
                         DISPPARAMS * pdispparams,
                         VARIANT * pvarResult,
                         EXCEPINFO * pexcepinfo,
                         UINT * puArgErr)
{
    // this parameter is a dead leftover from an earlier interface
    if (IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }
    
    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);
    
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pti->Invoke(
        (IVideoWindow *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);
    
    pti->Release();
    return hr;
}


// --- IBasicVideo implementation ----------


CBaseBasicVideo::CBaseBasicVideo(const TCHAR * pName,LPUNKNOWN punk) :
CUnknown(pName, punk)
{
}


// overriden to publicise our interfaces

STDMETHODIMP
CBaseBasicVideo::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if (riid == IID_IBasicVideo || riid == IID_IBasicVideo2) {
        return GetInterface( static_cast<IBasicVideo2 *>(this), ppv);
    } else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}

STDMETHODIMP
CBaseBasicVideo::GetTypeInfoCount(UINT * pctinfo)
{
    return m_basedisp.GetTypeInfoCount(pctinfo);
}


STDMETHODIMP
CBaseBasicVideo::GetTypeInfo(
                             UINT itinfo,
                             LCID lcid,
                             ITypeInfo ** pptinfo)
{
    return m_basedisp.GetTypeInfo(
        IID_IBasicVideo,
        itinfo,
        lcid,
        pptinfo);
}


STDMETHODIMP
CBaseBasicVideo::GetIDsOfNames(
                               REFIID riid,
                               OLECHAR  ** rgszNames,
                               UINT cNames,
                               LCID lcid,
                               DISPID * rgdispid)
{
    return m_basedisp.GetIDsOfNames(
        IID_IBasicVideo,
        rgszNames,
        cNames,
        lcid,
        rgdispid);
}


STDMETHODIMP
CBaseBasicVideo::Invoke(
                        DISPID dispidMember,
                        REFIID riid,
                        LCID lcid,
                        WORD wFlags,
                        DISPPARAMS * pdispparams,
                        VARIANT * pvarResult,
                        EXCEPINFO * pexcepinfo,
                        UINT * puArgErr)
{
    // this parameter is a dead leftover from an earlier interface
    if (IID_NULL != riid) {
        return DISP_E_UNKNOWNINTERFACE;
    }
    
    ITypeInfo * pti;
    HRESULT hr = GetTypeInfo(0, lcid, &pti);
    
    if (FAILED(hr)) {
        return hr;
    }
    
    hr = pti->Invoke(
        (IBasicVideo *)this,
        dispidMember,
        wFlags,
        pdispparams,
        pvarResult,
        pexcepinfo,
        puArgErr);
    
    pti->Release();
    return hr;
}


// --- Implementation of Deferred Commands ----------


CDispParams::CDispParams(UINT nArgs, VARIANT* pArgs)
{
    cNamedArgs = 0;
    rgdispidNamedArgs = NULL;
    cArgs = nArgs;
    
    if (cArgs) {
        rgvarg = new VARIANT[cArgs];
        
        for (UINT i = 0; i < cArgs; i++) {
            
            VARIANT * pDest = &rgvarg[i];
            VARIANT * pSrc = &pArgs[i];
            
            pDest->vt = pSrc->vt;
            switch(pDest->vt) {
                
            case VT_I4:
                pDest->lVal = pSrc->lVal;
                break;
                
            case VT_UI1:
                pDest->bVal = pSrc->bVal;
                break;
                
            case VT_I2:
                pDest->iVal = pSrc->iVal;
                break;
                
            case VT_R4:
                pDest->fltVal = pSrc->fltVal;
                break;
                
            case VT_R8:
                pDest->dblVal = pSrc->dblVal;
                break;
                
            case VT_BOOL:
                pDest->boolVal = pSrc->boolVal;
                break;
                
            case VT_ERROR:
                pDest->scode = pSrc->scode;
                break;
                
            case VT_CY:
                pDest->cyVal = pSrc->cyVal;
                break;
                
            case VT_DATE:
                pDest->date = pSrc->date;
                break;
                
            case VT_BSTR:
                if (pSrc->bstrVal == NULL) {
                    pDest->bstrVal = NULL;
                } else {
                    
                    // a BSTR is a WORD followed by a UNICODE string.
                    // the pointer points just after the WORD
                    
                    WORD len = * (WORD*) (pSrc->bstrVal - (sizeof(WORD) / sizeof(OLECHAR)));
                    OLECHAR* pch = new OLECHAR[len + (sizeof(WORD)/sizeof(OLECHAR))];
                    WORD *pui = (WORD*)pch;
                    *pui = len;
                    pDest->bstrVal = pch + (sizeof(WORD)/sizeof(OLECHAR));
                    CopyMemory(pDest->bstrVal, pSrc->bstrVal, len*sizeof(OLECHAR));
                }
                pDest->bstrVal = pSrc->bstrVal;
                break;
                
            case VT_UNKNOWN:
                pDest->punkVal = pSrc->punkVal;
                pDest->punkVal->AddRef();
                break;
                
            case VT_DISPATCH:
                pDest->pdispVal = pSrc->pdispVal;
                pDest->pdispVal->AddRef();
                break;
                
            default:
                // a type we haven't got round to adding yet!
                ASSERT(0);
                break;
            }
        }
        
    } else {
        rgvarg = NULL;
    }
    
}


CDispParams::~CDispParams()
{
    for (UINT i = 0; i < cArgs; i++) {
        switch(rgvarg[i].vt) {
        case VT_BSTR:
            if (rgvarg[i].bstrVal != NULL) {
                OLECHAR * pch = rgvarg[i].bstrVal - (sizeof(WORD)/sizeof(OLECHAR));
                delete pch;
            }
            break;
            
        case VT_UNKNOWN:
            rgvarg[i].punkVal->Release();
            break;
            
        case VT_DISPATCH:
            rgvarg[i].pdispVal->Release();
            break;
        }
    }
    delete[] rgvarg;
}


// lifetime is controlled by refcounts (see defer.h)

CDeferredCommand::CDeferredCommand(
                                   CCmdQueue * pQ,
                                   LPUNKNOWN    pUnk,
                                   HRESULT *    phr,
                                   LPUNKNOWN    pUnkExecutor,
                                   REFTIME  time,
                                   GUID*    iid,
                                   long dispidMethod,
                                   short    wFlags,
                                   long nArgs,
                                   VARIANT* pDispParams,
                                   VARIANT* pvarResult,
                                   short*   puArgErr,
                                   BOOL bStream
                                   ) :
CUnknown(NAME("DeferredCommand"), pUnk),
m_pQueue(pQ),
m_pUnk(pUnkExecutor),
m_iid(iid),
m_dispidMethod(dispidMethod),
m_wFlags(wFlags),
m_DispParams(nArgs, pDispParams),
m_pvarResult(pvarResult),
m_bStream(bStream),
m_hrResult(E_ABORT)

{
    // convert REFTIME to REFERENCE_TIME
    COARefTime convertor(time);
    m_time = convertor;
    
    // no check of time validity - it's ok to queue a command that's
    // already late
    
    // check iid is supportable on pUnk by QueryInterface for it
    IUnknown * pInterface;
    HRESULT hr = m_pUnk->QueryInterface(GetIID(), (void**) &pInterface);
    if (FAILED(hr)) {
        *phr = hr;
        return;
    }
    pInterface->Release();
    
    
    // !!! check dispidMethod and param/return types using typelib
    ITypeInfo *pti;
    hr = m_Dispatch.GetTypeInfo(*iid, 0, 0, &pti);
    if (FAILED(hr)) {
        *phr = hr;
        return;
    }
    // !!! some sort of ITypeInfo validity check here
    pti->Release();
    
    
    // Fix up the dispid for put and get
    if (wFlags == DISPATCH_PROPERTYPUT) {
        m_DispParams.cNamedArgs = 1;
        m_DispId = DISPID_PROPERTYPUT;
        m_DispParams.rgdispidNamedArgs = &m_DispId;
    }
    
    // all checks ok - add to queue
    hr = pQ->Insert(this);
    if (FAILED(hr)) {
        *phr = hr;
    }
}


// refcounts are held by caller of InvokeAt... and by list. So if
// we get here, we can't be on the list

#if 0
CDeferredCommand::~CDeferredCommand()
{
    // this assert is invalid since if the queue is deleted while we are
    // still on the queue, we will have been removed by the queue and this
    // m_pQueue will not have been modified.
    // ASSERT(m_pQueue == NULL);
    
    // we don't hold a ref count on pUnk, which is the object that should
    // execute the command.
    // This is because there would otherwise be a circular refcount problem
    // since pUnk probably owns the CmdQueue object that has a refcount
    // on us.
    // The lifetime of pUnk is guaranteed by it being part of, or lifetime
    // controlled by, our parent object. As long as we are on the list, pUnk
    // must be valid. Once we are off the list, we do not use pUnk.
    
}
#endif


// overriden to publicise our interfaces

STDMETHODIMP
CDeferredCommand::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
    ValidateReadWritePtr(ppv,sizeof(PVOID));
    if (riid == IID_IDeferredCommand) {
        return GetInterface( (IDeferredCommand *) this, ppv);
    } else {
        return CUnknown::NonDelegatingQueryInterface(riid, ppv);
    }
}


// remove from q. this will reduce the refcount by one (since the q
// holds a count) but can't make us go away since he must have a
// refcount in order to call this method.

STDMETHODIMP
CDeferredCommand::Cancel()
{
    if (m_pQueue == NULL) {
        return VFW_E_ALREADY_CANCELLED;
    }
    
    HRESULT hr = m_pQueue->Remove(this);
    if (FAILED(hr)) {
        return hr;
    }
    
    m_pQueue = NULL;
    return S_OK;
}


STDMETHODIMP
CDeferredCommand::Confidence(LONG* pConfidence)
{
    return E_NOTIMPL;
}


STDMETHODIMP
CDeferredCommand::GetHResult(HRESULT * phrResult)
{
    CheckPointer(phrResult,E_POINTER);
    ValidateReadWritePtr(phrResult,sizeof(HRESULT));
    
    if (m_pQueue != NULL) {
        return E_ABORT;
    }
    *phrResult = m_hrResult;
    return S_OK;
}


// set the time to be a new time (checking that it is valid) and
// then requeue

STDMETHODIMP
CDeferredCommand::Postpone(REFTIME newtime)
{
    
    // check that this time is not past
    // convert REFTIME to REFERENCE_TIME
    COARefTime convertor(newtime);
    
    // check that the time has not passed
    if (m_pQueue->CheckTime(convertor, IsStreamTime())) {
        return VFW_E_TIME_ALREADY_PASSED;
    }
    
    // extract from list
    HRESULT hr = m_pQueue->Remove(this);
    if (FAILED(hr)) {
        return hr;
    }
    
    // change time
    m_time = convertor;
    
    // requeue
    hr = m_pQueue->Insert(this);
    
    return hr;
}


HRESULT
CDeferredCommand::Invoke()
{
    // check that we are still outstanding
    if (m_pQueue == NULL) {
        return VFW_E_ALREADY_CANCELLED;
    }
    
    // get the type info
    ITypeInfo* pti;
    HRESULT hr = m_Dispatch.GetTypeInfo(GetIID(), 0, 0, &pti);
    if (FAILED(hr)) {
        return hr;
    }
    
    // qi for the expected interface and then invoke it. Note that we have to
    // treat the returned interface as IUnknown since we don't know its type.
    IUnknown* pInterface;
    
    hr = m_pUnk->QueryInterface(GetIID(), (void**) &pInterface);
    if (FAILED(hr)) {
        pti->Release();
        return hr;
    }
    
    EXCEPINFO expinfo;
    UINT uArgErr;
    m_hrResult = pti->Invoke(
        pInterface,
        GetMethod(),
        GetFlags(),
        GetParams(),
        GetResult(),
        &expinfo,
        &uArgErr);
    
    // release the interface we QI'd for
    pInterface->Release();
    pti->Release();
    
    
    // remove from list whether or not successful
    // or we loop indefinitely
    hr = m_pQueue->Remove(this);
    m_pQueue = NULL;
    return hr;
}



// --- CCmdQueue methods ----------


CCmdQueue::CCmdQueue() :
m_listPresentation(NAME("Presentation time command list")),
m_listStream(NAME("Stream time command list")),
m_evDue(TRUE),    // manual reset
m_dwAdvise(0),
m_pClock(NULL),
m_bRunning(FALSE)
{
}


CCmdQueue::~CCmdQueue()
{
    // empty all our lists
    
    // we hold a refcount on each, so traverse and Release each
    // entry then RemoveAll to empty the list
    POSITION pos = m_listPresentation.GetHeadPosition();
    
    while(pos) {
        CDeferredCommand* pCmd = m_listPresentation.GetNext(pos);
        pCmd->Release();
    }
    m_listPresentation.RemoveAll();
    
    pos = m_listStream.GetHeadPosition();
    
    while(pos) {
        CDeferredCommand* pCmd = m_listStream.GetNext(pos);
        pCmd->Release();
    }
    m_listStream.RemoveAll();
    
    if (m_pClock) {
        if (m_dwAdvise) {
            m_pClock->Unadvise(m_dwAdvise);
            m_dwAdvise = 0;
        }
        m_pClock->Release();
    }
}


// returns a new CDeferredCommand object that will be initialised with
// the parameters and will be added to the queue during construction.
// returns S_OK if successfully created otherwise an error and
// no object has been queued.

HRESULT
CCmdQueue::New(
               CDeferredCommand **ppCmd,
               LPUNKNOWN    pUnk,       // this object will execute command
               REFTIME  time,
               GUID*    iid,
               long dispidMethod,
               short    wFlags,
               long cArgs,
               VARIANT* pDispParams,
               VARIANT* pvarResult,
               short*   puArgErr,
               BOOL bStream
               )
{
    CAutoLock lock(&m_Lock);
    
    HRESULT hr = S_OK;
    *ppCmd = NULL;
    
    CDeferredCommand* pCmd;
    pCmd = new CDeferredCommand(
        this,
        NULL,       // not aggregated
        &hr,
        pUnk,       // this guy will execute
        time,
        iid,
        dispidMethod,
        wFlags,
        cArgs,
        pDispParams,
        pvarResult,
        puArgErr,
        bStream);
    
    if (pCmd == NULL) {
        hr = E_OUTOFMEMORY;
    } else {
        *ppCmd = pCmd;
    }
    return hr;
}


HRESULT
CCmdQueue::Insert(CDeferredCommand* pCmd)
{
    CAutoLock lock(&m_Lock);
    
    // addref the item
    pCmd->AddRef();
    
    CGenericList<CDeferredCommand> * pList;
    if (pCmd->IsStreamTime()) {
        pList = &m_listStream;
    } else {
        pList = &m_listPresentation;
    }
    POSITION pos = pList->GetHeadPosition();
    
    // seek past all items that are before us
    while (pos &&
        (pList->Get(pos)->GetTime() <= pCmd->GetTime())) {
        
        pList->GetNext(pos);
    }
    
    // now at end of list or in front of items that come later
    if (!pos) {
        pList->AddTail(pCmd);
    } else {
        pList->AddBefore(pos, pCmd);
    }
    
    SetTimeAdvise();
    return S_OK;
}


HRESULT
CCmdQueue::Remove(CDeferredCommand* pCmd)
{
    CAutoLock lock(&m_Lock);
    HRESULT hr = S_OK;
    
    CGenericList<CDeferredCommand> * pList;
    if (pCmd->IsStreamTime()) {
        pList = &m_listStream;
    } else {
        pList = &m_listPresentation;
    }
    POSITION pos = pList->GetHeadPosition();
    
    // traverse the list
    while (pos && (pList->Get(pos) != pCmd)) {
        pList->GetNext(pos);
    }
    
    // did we drop off the end?
    if (!pos) {
        hr = VFW_E_NOT_FOUND;
    } else {
        
        // found it - now take off list
        pList->Remove(pos);
        
        // Insert did an AddRef, so release it
        pCmd->Release();
        
        // check that timer request is still for earliest time
        SetTimeAdvise();
    }
    return hr;
}


// set the clock used for timing

HRESULT
CCmdQueue::SetSyncSource(IReferenceClock* pClock)
{
    CAutoLock lock(&m_Lock);
    
    // addref the new clock first in case they are the same
    if (pClock) {
        pClock->AddRef();
    }
    
    // kill any advise on the old clock
    if (m_pClock) {
        if (m_dwAdvise) {
            m_pClock->Unadvise(m_dwAdvise);
            m_dwAdvise = 0;
        }
        m_pClock->Release();
    }
    m_pClock = pClock;
    
    // set up a new advise
    SetTimeAdvise();
    return S_OK;
}


// set up a timer event with the reference clock

void
CCmdQueue::SetTimeAdvise(void)
{
    // make sure we have a clock to use
    if (!m_pClock) {
        return;
    }
    
    // reset the event whenever we are requesting a new signal
    m_evDue.Reset();
    
    // time 0 is earliest
    CRefTime current;
    
    // find the earliest presentation time
    if (m_listPresentation.GetCount() > 0) {
        
        POSITION pos = m_listPresentation.GetHeadPosition();
        current = m_listPresentation.Get(pos)->GetTime();
    }
    
    // if we're running, check the stream times too
    if (m_bRunning) {
        
        CRefTime t;
        
        if (m_listStream.GetCount() > 0) {
            
            POSITION pos = m_listStream.GetHeadPosition();
            t = m_listStream.Get(pos)->GetTime();
            
            // add on stream time offset to get presentation time
            t += m_StreamTimeOffset;
            
            // is this earlier?
            if ((current == TimeZero) || (t < current)) {
                current = t;
            }
        }
    }
    
    // need to change?
    if ((current > TimeZero) && (current != m_tCurrentAdvise)) {
        if (m_dwAdvise) {
            m_pClock->Unadvise(m_dwAdvise);
            // reset the event whenever we are requesting a new signal
            m_evDue.Reset();
        }
        
        // ask for time advice - the first two params are either
        // stream time offset and stream time or
        // presentation time and 0. we always use the latter
        HRESULT hr = m_pClock->AdviseTime(
            (REFERENCE_TIME)current,
            TimeZero,
            (HEVENT) HANDLE(m_evDue),
            &m_dwAdvise);
        
        ASSERT(SUCCEEDED(hr));
        m_tCurrentAdvise = current;
    }
}


// switch to run mode. Streamtime to Presentation time mapping known.

HRESULT
CCmdQueue::Run(REFERENCE_TIME tStreamTimeOffset)
{
    CAutoLock lock(&m_Lock);
    
    m_StreamTimeOffset = tStreamTimeOffset;
    m_bRunning = TRUE;
    
    // ensure advise is accurate
    SetTimeAdvise();
    return S_OK;
}


// switch to Stopped or Paused mode. Time mapping not known.

HRESULT
CCmdQueue::EndRun()
{
    CAutoLock lock(&m_Lock);
    
    m_bRunning = FALSE;
    
    // check timer setting - stream times
    SetTimeAdvise();
    return S_OK;
}


// return a pointer to the next due command. Blocks for msTimeout
// milliseconds until there is a due command.
// Stream-time commands will only become due between Run and Endrun calls.
// The command remains queued until invoked or cancelled.
// Returns E_ABORT if timeout occurs, otherwise S_OK (or other error).
//
// returns an AddRef'd object

HRESULT
CCmdQueue::GetDueCommand(CDeferredCommand ** ppCmd, long msTimeout)
{
    // loop until we timeout or find a due command
    for (;;) {
        
        {
            CAutoLock lock(&m_Lock);
            
            
            // find the earliest command
            CDeferredCommand * pCmd = NULL;
            
            // check the presentation time and the
            // stream time list to find the earliest
            
            if (m_listPresentation.GetCount() > 0) {
                POSITION pos = m_listPresentation.GetHeadPosition();
                pCmd = m_listPresentation.Get(pos);
            }
            
            if (m_bRunning && (m_listStream.GetCount() > 0)) {
                POSITION pos = m_listStream.GetHeadPosition();
                CDeferredCommand* pStrm = m_listStream.Get(pos);
                
                CRefTime t = pStrm->GetTime() + m_StreamTimeOffset;
                if (!pCmd || (t < pCmd->GetTime())) {
                    pCmd = pStrm;
                }
            }
            
            //  if we have found one, is it due?
            if (pCmd) {
                if (CheckTime(pCmd->GetTime(), pCmd->IsStreamTime())) {
                    
                    // yes it's due - addref it
                    pCmd->AddRef();
                    *ppCmd = pCmd;
                    return S_OK;
                }
            }
        }
        
        // block until the advise is signalled
        if (WaitForSingleObject(m_evDue, msTimeout) != WAIT_OBJECT_0) {
            return E_ABORT;
        }
    }
}


// return a pointer to a command that will be due for a given time.
// Pass in a stream time here. The stream time offset will be passed
// in via the Run method.
// Commands remain queued until invoked or cancelled.
// This method will not block. It will report E_ABORT if there are no
// commands due yet.
//
// returns an AddRef'd object

HRESULT
CCmdQueue::GetCommandDueFor(REFERENCE_TIME rtStream, CDeferredCommand**ppCmd)
{
    CAutoLock lock(&m_Lock);
    
    CRefTime tStream(rtStream);
    
    // find the earliest stream and presentation time commands
    CDeferredCommand* pStream = NULL;
    if (m_listStream.GetCount() > 0) {
        POSITION pos = m_listStream.GetHeadPosition();
        pStream = m_listStream.Get(pos);
    }
    CDeferredCommand* pPresent = NULL;
    if (m_listPresentation.GetCount() > 0) {
        POSITION pos = m_listPresentation.GetHeadPosition();
        pPresent = m_listPresentation.Get(pos);
    }
    
    // is there a presentation time that has passed already
    if (pPresent && CheckTime(pPresent->GetTime(), FALSE)) {
        pPresent->AddRef();
        *ppCmd = pPresent;
        return S_OK;
    }
    
    // is there a stream time command due before this stream time
    if (pStream && (pStream->GetTime() <= tStream)) {
        pPresent->AddRef();
        *ppCmd = pStream;
        return S_OK;
    }
    
    // if we are running, we can map presentation times to
    // stream time. In this case, is there a presentation time command
    // that will be due before this stream time is presented?
    if (m_bRunning && pPresent) {
        
        // this stream time will appear at...
        tStream += m_StreamTimeOffset;
        
        // due before that?
        if (pPresent->GetTime() <= tStream) {
            *ppCmd = pPresent;
            return S_OK;
        }
    }
    
    // no commands due yet
    return VFW_E_NOT_FOUND;
}

